523 U.S. 303 (1998)
In March 1992, Edward G. Scheffer, an airman stationed at March Air Force Base in California, volunteered to work as an informant on drug investigations for the Air Force Office of Special Investigations.1 His OSI supervisors advised him that they would ask him to submit to drug testing and polygraph examinations from time to time during his undercover work.2 In early April, one of the OSI agents supervising Scheffer requested that he submit to a urine test.3 Shortly after providing the urine sample, but before the results were known, Scheffer agreed to take a polygraph test administered by an OSI examiner, who concluded that the test indicated no deception when Scheffer denied using drugs since joining the Air Force.4
On April 30, Scheffer unaccountably failed to appear for work and could not be found on the base.5 He remained absent without leave until May 13, when an Iowa state patrolman arrested him following a routine traffic stop and held him for return to the base.6 OSI agents later learned that Scheffer's urinalysis revealed the presence of methamphetamine.7 Scheffer was tried by general court-martial on charges of using methamphetamine, failing to go to his appointed place of duty, wrongfully absenting himself from the base for 13 days, and, with respect to an unrelated matter, uttering 17 insufficient funds checks.8
At trial Scheffer testified on his own behalf, relying upon an innocent ingestion theory and denying that he had knowingly used drugs while working for OSI.9 On cross-examination the prosecution attempted to impeach him with inconsistencies between his trial testimony and earlier statements he had made to OSI.10 Scheffer sought to introduce the polygraph evidence in support of his testimony that he did not knowingly use drugs, but the military judge denied the motion and excluded the evidence pursuant to Military Rule of Evidence 707.11 Scheffer was convicted on all counts and sentenced to a bad-conduct discharge, confinement for 30 months, total forfeiture of all pay and allowances, and reduction to the lowest enlisted grade.12
The Air Force Court of Criminal Appeals affirmed in all material respects.13 By a 3-to-2 vote the United States Court of Appeals for the Armed Forces reversed.14 The Supreme Court granted certiorari.15
Whether Military Rule of Evidence 707's per se exclusion of polygraph evidence violates an accused service member's constitutional right to present a defense?16
A defendant's right to present relevant evidence is subject to reasonable restrictions that accommodate other legitimate interests in the criminal trial process.17 State and federal rulemakers therefore possess broad latitude to establish rules excluding evidence, provided the rules are not arbitrary or disproportionate to the purposes they serve.18 Exclusion of evidence rises to constitutional violation only when it infringes a weighty interest of the accused.19
No. Military Rule of Evidence 707 applies uniformly to all witnesses and parties and therefore does not single out any particular class for disfavor.20 The rule advances three legitimate governmental interests.21 These include ensuring that only reliable evidence reaches the factfinder.22 The rule also preserves the court members' exclusive role in assessing credibility.23
Finally, it prevents protracted collateral litigation over polygraph methodology and examiner qualifications.24 Scheffer remained free to testify at length about his innocent-ingestion defense.25 He could introduce any factual evidence bearing on the charged offenses.26 The rule merely barred him from presenting expert opinion testimony that would have bolstered his credibility.27
Because the exclusion left intact his ability to convey his version of events and did not undermine any fundamental element of the defense, it did not infringe a weighty interest of the accused.28
Military Rule of Evidence 707 does not unconstitutionally abridge the right to present a defense.29
Related opinions on this issue
Joined by O'connor, Ginsburg, And Breyer, Jj.
Justice Kennedy joined the principal opinion's conclusion that differing jurisdictions may reasonably reach different conclusions about polygraph reliability.30 He therefore concurred in the judgment that the per se rule is not arbitrary or disproportionate.31 He nevertheless expressed doubt that categorical exclusion is wise policy.32
He rejected the principal opinion's additional reliance on protecting the jury's credibility function.33 Such reasoning demeans jurors' competence.34 It also contradicts the modern rejection of the ultimate-issue prohibition embodied in Rule 704.35
Justice Stevens dissented on the ground that a blanket prohibition deprives the accused of relevant exculpatory evidence.36 He argued for case-by-case assessment of reliability.37 He emphasized that the results here constituted independent factual support for the innocent-ingestion defense.38
The test was obtained only three days after the urinalysis.39 The government's own extensive use of polygraphs in non-trial settings undermined its claim of unreliability.40 In his view the three asserted interests do not justify a categorical rule.41
Such a rule may be outcome-determinative in many cases.